JINDO, South Korea (CNN) — An arrest warrant was issued Friday for the captain of the ferry that sank off the coast of South Korea, an accident that killed 29 people and left nearly 270 missing.

Two other crew members also face arrest, a spokesman for the joint prosecutor and police investigators said Friday.

The spokesman did not provide any further detail.

The cause of the accident still isn’t known. But a South Korean prosecutor said the captain, Lee Joon Suk, wasn’t in the steering room when the Sewol started to sink; a third mate was at the helm.

“It is not clear where (the captain) was when the accident occurred, although it is clear that he was not in the steering room before the actual accident happened,” state prosecutor Jae-Eok Park said Friday.

The captain was one of at least 174 people rescued soon after Wednesday’s sinking.

The charges against the captain were not announced, but it is possible he could be charged with dereliction of duty and even attempted murder, maritime law attorney Jack Hickey told CNN.

“This captain violated the age-old rule and internationally recognized rule that a captain must stay on the vessel,” Hickey said.

He added, “Pretty much every law, rule, regulation and standard throughout the world says that yes, the captain must stay with the ship until all personnel are safely off of the ship, certainly passengers.”

Compounding the tragedy of the ship sinking, one of those rescued, a high school vice principal who was on board the ferry along with more than 300 students, was found hanging from a tree, police said.

Kang Min Kyu, 52, vice principal of Ansan Danwon High School, was among the first survivors to be rescued.

Police said he apparently hanged himself with a belt from a tree near a gymnasium in Jindo, where distraught relatives of missing passengers have been camping out.

Meanwhile, divers raced to reach the hundreds of people still believed to be inside the ship.

Divers breached the hull of the sunken ferry Friday, and two managed to enter the second deck — the cargo deck, the South Korean coast guard said. But rough waters forced them back out again. They didn’t find any bodies in their brief search.

“The guide line that links the sunken ship and the rescue vessel has been cut off,” the coast guard said. “Still, the entrance into the ship is open, and we plan to resume operation to enter the ship.”

It’s a race against time.

Hopes of finding the missing dimmed further when the entire boat became submerged Friday. Until then, part of the ship’s blue-and-white hull was still poking out of the frigid waters of the Yellow Sea.

“There are heavy currents in the area. So the vessel itself is not stable in the water. So you are, by default, putting divers at risk,” U.S. Navy Capt. Heidi Agle told CNN’s Wolf Blitzer. The U.S. Navy is assisting with the South Korean search.

Anger and disgust

Relatives of passengers expressed increasing disgust and anger about the lack of explanation from the captain and the pace of the rescue effort.

Some have waited for days in the cold rain at a harbor in Jindo, about 20 kilometers (12 miles) from the sunken boat.

Others camped out at a nearby gymnasium and auditorium, desperate to hear any news of their loved ones. Relatives overcome with emotion howled and screamed, but to no avail.

“Hurry up, find it faster!” one woman wailed.

Several collapsed. At least two women were taken away on stretchers.

Part of the frustration stems from the conflicting information reported by officials.

In the hours after the sinking, some analysts speculated the ferry may have veered off course and struck an object. But the South Korean Ministry of Oceans and Fisheries said Thursday that it had approved the boat’s intended route, and the actual course did not deviate significantly.

Yet Kim Soo Hyeon, chief of South Korea’s Yellow Sea Maritime Police Agency, later said the ship apparently deviated from its planned route but did not appear to have hit a rock.

The Ministry of Ocean and Fisheries released a transcript of the conversation between the ferry and center that monitors vessel traffic.

After alerting the center that the ferry was rolling, the Sewol stated that “the body of the ship is tilted to the left. Containers fell over, too.”

The control center then asked if people were hurt. Impossible to confirm because it was impossible to move, the ferry responded.

The center told the ferry crew to get people ready for evacuation, and the ferry once again described how hard it was for people to move.

Adding to the pain for families, police said texts and social media messages claiming to be from missing passengers turned out to be fake.

Media outlets, including CNN, shared the texts with a wide audience.

“We will investigate people sending out these messages,” said Lee Sung Yoon, head of the combined police and prosecution team.

He said authorities will go after those behind the hoaxes and will “punish them severely.”

Cranes arrive

The coast guard said workers continued to pump air into the hull of the submerged ship Friday but could not stop its descent.

Any hope for survival largely hinges on whether passengers may be floundering in air pockets within the ship, which isn’t unheard of in such cases.

In May 2013, a tugboat capsized off West Africa. Rescuers pulled out a man from 100 feet below the surface who survived 2½ days inside a 4-square-foot air pocket.

That’s one reason family members aren’t ready to give up hope.

“When they’re in a small compartment … with an air bubble, they really have to stay calm and breathe shallow and conserve the oxygen in that space,” former Navy diver Bobbie Scholley told CNN.

But in the case of the South Korean ferry, there’s another challenge to contend with: time and temperature.

“Absolutely, there could be areas in there where there is breathable air,” said Mike Dean, the U.S. Navy deputy director for salvage and diving. “But the trouble right now is the temperature and getting people to them.”

Adding to the relatives’ despair was the arrival of three 3,600-ton seaborne cranes. They fear the cranes’ presence means the mission is shifting from a search to a salvage effort.

A fourth crane will arrive later.

A coast guard official assured families that nothing would be done to jeopardize the safety of possible survivors.

“Let me be clear,” Kim told journalists. “There won’t be any salvaging work done against the will of the bereaved families.”